CF629B.Far Relative’s Problem

Famil Door wants to celebrate his birthday with his friends from Far Far Away. He has n friends and each of them can come to the party in a specific range of days of the year from a__i to b__i. Of course, Famil Door wants to have as many friends celebrating together with him as possible.

Far cars are as weird as Far Far Away citizens, so they can only carry two people of opposite gender, that is exactly one male and one female. However, Far is so far from here that no other transportation may be used to get to the party.

Famil Door should select some day of the year and invite some of his friends, such that they all are available at this moment and the number of male friends invited is equal to the number of female friends invited. Find the maximum number of friends that may present at the party.

Famil Door 想要与来自“远得不能再远”（Far Far Away）的朋友们一起庆祝他的生日。他有 $n$ 位朋友，每位朋友只能在一年中的某一天区间 $[a_i, b_i]$ 内参加聚会。显然，Famil Door 希望尽可能多地邀请朋友与他一同庆祝。

然而，“远地汽车”（Far cars）和“远得不能再远”的居民一样古怪：它们每次最多只能载运两人，且必须是一男一女（即恰好一名男性和一名女性）。此外，由于“远得不能再远”距离此处实在太过遥远，前往聚会的唯一交通方式就是这种远地汽车。

Famil Door 需要选定一年中的某一天，并邀请其中一部分朋友——这些朋友在该天都必须有空，且被邀请的男性朋友人数必须等于被邀请的女性朋友人数。请找出可能出席聚会的朋友人数的最大值。

The first line of the input contains a single integer n (1 ≤ n ≤ 5000) — then number of Famil Door's friends.

Then follow n lines, that describe the friends. Each line starts with a capital letter 'F' for female friends and with a capital letter 'M' for male friends. Then follow two integers a__i and b__i (1 ≤ a__i ≤ b__i ≤ 366), providing that the i-th friend can come to the party from day a__i to day b__i inclusive.

输入的第一行包含一个整数 $n$（$1 ≤ n ≤ 5000$）——即 Famil Door 的朋友人数。

接下来是 $n$ 行，用于描述这些朋友。每行以大写字母 'F' 开头表示该朋友为女性，以大写字母 'M' 开头表示该朋友为男性。随后是两个整数 $a_i$ 和 $b_i$（$1 ≤ a_i ≤ b_i ≤ 366$），表示第 $i$ 位朋友可在第 $a_i$ 天至第 $b_i$ 天（含端点）期间参加聚会。

Print the maximum number of people that may come to Famil Door's party.

输出可能参加 Famil Door 家庭聚会的最大人数。

In the first sample, friends 3 and 4 can come on any day in range [117, 128].

In the second sample, friends with indices 3, 4, 5 and 6 can come on day 140.

在第一个样例中，朋友 3 和 4 可以在区间 $[117,\,128]$ 内的任意一天到来。

在第二个样例中，索引为 3、4、5 和 6 的朋友可以在第 140 天到来。